Conventionally, as a method of molding a composite material, such as CFRP (carbon fiber reinforced plastics) and GFRP (glass fiber reinforced plastics), a method of using A/C (autoclave) molding equipment is known.
In a molding method using the conventional autoclave molding equipment, sheet-like prepregs are laminated on a jig (a mold or a molding jig) which fits a shape of a finished product. Next, the sheet-like prepregs are covered using a bag film, a sealant and so on. Subsequently, a region covered by the bag film and the sealant is made into a vacuum state. Thereby, the prepregs covered by the bag film and the sealant become in a pressurized state by the atmospheric pressure. The work that seals prepregs by vacuuming with a bag film and a sealant is called bagging. Next, the prepregs after the bagging are conveyed in autoclave molding equipment. Then, the prepregs are cured by heating using the autoclave molding equipment. Thereby, the cured prepregs are obtained as a molded product of a composite material.
In the case of molding a composite material using the conventional autoclave molding equipment, prepregs are heated and cured by a circulation of hot air. Nitrogen may also be filled for a purpose of an increase in pressure and inactivation under a high temperature. However, it is difficult for the conventional autoclave molding equipment, which heats a molded product by hot air, to improve low uniformity of temperature and raise temperature instantly. The low uniformity of temperature leads to deterioration of an appearance or an internal quality of a molded product. Therefore, it is difficult for the conventional autoclave molding equipment, which heats a molded product by hot air, to cure a molded product, having a complicated structure, or a molded product, having a large size, uniformly in a satisfactory quality.
Thus, autoclave molding equipment which heats a molded product by steam instead of hot air has been devised (for example, refer to Japanese Patent Application Publication JP 2012-153133 A). In the case of using steam as a heating medium by a heat transfer, uniformity of temperature can be dramatically improved compared to the case of using hot air or nitrogen. Therefore, in the case of using the autoclave molding equipment which heats a molded product with steam, even a product having a complicated structure can also be molded.
Specifically, when shaping of prepregs is previously performed by a shaping device, even a molded product, having a complicated structure, can be heated and cured using steam type autoclave molding equipment. The shaping of prepregs by a shaping device is typically shaping processing which warms laminated sheet-like prepregs to a temperature appropriate for the shaping and subsequently shapes the warmed sheet-like prepregs. Therefore, sheet-like prepregs shaped by a shaping device are heated and cured by steam type autoclave molding equipment. Note that, the forming of prepregs before curing of the prepregs is generally called “shaping” in order to distinguish from the forming of prepregs by curing of the prepregs.
An object of the present invention is to manufacture a molded product of a composite material, having a complicated structure, more simply.